Oral Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2022

Electronic (e)-cigarettes are a diverse group of battery-powered devices that aerosolise a liquid, usually containing nicotine, for inhalation. Use is becoming increasingly common, especially among youth.

Nicotine is one of the most addictive substances known. This session will report on a systematic review of the contemporary evidence on the health effects of e-cigarette, largely relating to nicotine products. Overall, 401 studies across 20 different health outcomes were included, of which 31 studies related to dependence, finding:

• Substantial evidence that use of e-cigarettes results in dependence on e-cigarettes among non-smokers and limited evidence for smokers.
• Insufficient evidence that e-cigarette dependence was associated with earlier age of initiation, daily use and later generation devices.
• Insufficient evidence that the relation of e-cigarette use to dependence remains stable over time among smokers and non-smokers.

In addition to the direct health effects of e-cigarettes, e-cigarettes have the ability to indirectly impact health by influencing smoking behaviour – an exceptionally harmful health behaviour. There is strong evidence that e-cigarettes increase combustible smoking uptake in non-smokers, particularly youth, by an average of three-fold and limited evidence that in the clinical setting freebase nicotine e-cigarettes are an efficacious smoking cessation aid. There is limited evidence that ex-smokers who use e-cigarettes, compared to those that do not, have around double the likelihood of smoking relapse.

The most common pattern of e-cigarettes is dual use (use in combination with smoking). Such use may result in the prolongation of smoking by seeming to help smokers to offset important tobacco control measures – for example, by being cheaper and more socially acceptable than smoking, by permitting use where smoking is banned and by being perceived as less harmful to health.